Copyright (c) 2017 Alexander Motin <mav@FreeBSD.org>
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$FreeBSD: stable/11/share/man/man4/ntb.4 323453 2017-09-11 18:48:09Z mav $

.Dd September 2, 2017 .Dt NTB 4 .Os .Sh NAME .Nm ntb .Nd Non-Transparent Bridge subsystem .Sh SYNOPSIS To compile it into your kernel, place the following lines in your kernel configuration file: d -ragged -offset indent .Cd "device ntb" .Ed

p Or, to load it as a module at boot, place the following line in .Xr loader.conf 5 : d -literal -offset indent ntb_load="YES" .Ed

p The following tunables are settable from the .Xr loader 8 : l -ohang t Va hw.ntb.debug_level Driver debug level. The default value is 0, higher means more verbose. t Va hint.ntb_hw. Ns Ar X Ns Va .config Configures a set of NTB functions, separated by commas, and their resource allocation. Each function can be configured as: "[<name>][:<mw>[:<spad>[:<db>]]]", where: .Va name is a name of the driver to attach (empty means any), .Va mw is a number of memory windows to allocate (empty means all available), .Va spad is a number of scratchpad registers to allocate (empty means all available), .Va db is a number of doorbells to allocate (empty means all available). The default configuration is empty string, which means single function with all available resources, allowing any driver to attach. .El .Sh DESCRIPTION Non-Transparent Bridges allow to connect two computer systems with PCIe link(s), providing each of them limited access to others memory space, scratchpad registers and interrupts. The .Nm subsystem uses those resources provided in generic way by hardware drivers and splits them between several functions, according to specified configuration. .Sh SEE ALSO .Xr if_ntb 4 , .Xr ntb_transport 4 , .Xr ntb_hw_intel 4 , .Xr ntb_hw_plx 4 .Sh AUTHORS .An -nosplit The .Nm subsystem was developed by Intel and originally written by .An Carl Delsey Aq Mt carl@FreeBSD.org . Later improvements were done by .An Conrad E. Meyer Aq Mt cem@FreeBSD.org and .An Alexander Motin Aq Mt mav@FreeBSD.org .